1. Field of the Invention
This invention relates generally to conveyors, and more particularly to a conveyor arrangement for recycling partially cooled asphalt.
2. Description of Related Art
Asphalt which has been prepared for paving is loaded from a silo into a dump truck which carries the asphalt to the location where it is to be used. This asphalt is at a temperature of between 300.degree. and 320.degree. F. The asphalt is dumped into a paving machine which spreads a layer of desired thickness.
Unplanned interruptions in the paving work because of rain, equipment breakdowns, etc. result in one or more truckloads of asphalt which cannot be unloaded into the paving machine and which is ordinarily returned to the asphalt plant and dumped on the ground before it hardens in the truck. This asphalt is now generally between 250.degree. and 280.degree. F.
A need exists, consequently, for apparatus to appropriately treat and return this unused hot mix asphalt to the silo for subsequent use.
U.S. Pat. No. 4,136,964, Swisher, Jr., entitled: "Apparatus for Simultaneously Mixing and Conveying Particulate Material", discloses a conveyor having a plurality of lifting surfaces forming a continuous belt. The conveyor also mixes aggregate with the asphalt solution to form hot mix asphalt and is provided with heating devices.
U.S. Pat. No. 4,458,847, Petersen, entitled: "Dosage Granulator for Tearing Up a Material of High Viscosity", discloses a granulator which is intended to granulate returned asphalt of high viscosity.
U.S. Pat. No. 4,483,620, Shinohara et al., entitled: "Regenerative Heating and Melting Device for Recovered Asphalt Concrete Rubble", discloses apparatus for treating hardened asphalt rubble for reuse.
The foregoing patents do not disclose apparatus for receiving returned asphalt which is at a temperature of from 250 to 280 degrees F. directly from a dump truck and treating it for return to the silo.
It is therefore an object of this invention to provide an asphalt recycling conveyor which reduces the viscosity of returned hot mix asphalt and returns the asphalt for reuse.
It is also an object of this invention to provide an conveyor which will deliver the treated returned asphalt to a silo.
It is another object of this invention to provide an asphalt recycling conveyor which will convert a bulk mass of returned asphalt into a continuous stream.
It is a further object of this invention to provide an asphalt recycling conveyor which will provide protection from injury for personnel operating the system.
In accordance with these and other objects, which will become apparent hereafter, the instant invention will now be described with reference to the accompanying drawings.